| 摘要 |
<p>An image data illegal use prevention system includes an image data fetching unit (6) for fetching digital image data in which electronic watermark data may be embedded, and an electronic watermark data detection unit (8) for detecting electronic watermark data from the image data fetched by the image data fetching unit (6). If electronic watermark data are detected by the electronic watermark data detection unit (8), then an image data recording unit (7) does not record the image data fetched by the image data fetching unit (6) onto a recording medium (9), thereby preventing illegal duplication. The electronic watermark data are calculated, for example, in accordance with an expression determined in advance for frequency components of discrete cosine transformed digital image data.</p> |
